The present disclosure relates to a signal processing device that performs a signal process on a digital audio signal output to a sound reproduction device such as so-called headphones or earphones, and in particular, to a signal processing device and a method for the same that can perform a noise cancellation process regardless of a sampling frequency of the digital audio signal.
Techniques of converting a sampling frequency of a digital audio signal to an arbitrary sampling frequency are disclosed in Japanese Laid-Open Patent Publication No. 2002-158619 and Japanese Laid-Open Patent Publication No. H07-212190. A technique of causing a digital circuit to cancel external noises heard when audio signals of content such as a musical composition are reproduced by a headphone device is disclosed in Japanese Laid-Open Patent Publication No. 2008-193421.
The audio signal is reproduced from a music medium, for example, from a recording medium such as a compact disc (CD) and a digital versatile disc (DVD), or is input to an optical cable or a coaxial cable by a Sony Philips Digital Interface (SPDIF) or input to a signal processing device, and so forth by wireless communication such as Bluetooth. The signal processing device then performs, for example, a noise cancellation process, and so forth on the audio signal, and the audio signal processed by the signal processing device is then supplied to and reproduced in a music reproduction device such as headphones.